2checkout is not working (1.4.8)

Hi

I set up 2chekout module but it is not working correctly.

I set correctly the return link on 2checkout admin panel but when it send me back to opencart its going to homepage and the order is not registered in opencart.

I have searched here in forum and there is a topic about this http://forum.opencart.com/viewtopic.php?f=22&t=11561 but I can't download the file posted by ipse (http://forum.opencart.com/download/file.php?id=1917). the file is corrupted.

Can any one give me some help on this?